Replacing CPU


O

Occidental

My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)? I understand that if you take a hard drive out of one PC and
install it in another, Windows will not work, so there must be
something in the original hardware that the Windows OS recognizes. Is
it the specific CPU, or something else on the motherboard?
 
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P

Paul

Occidental said:
My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)? I understand that if you take a hard drive out of one PC and
install it in another, Windows will not work, so there must be
something in the original hardware that the Windows OS recognizes. Is
it the specific CPU, or something else on the motherboard?

WinXP or later OS, have "Activation" to keep track of whether
the hardware being used has changed. This article hints at how
that works.

http://aumha.org/win5/a/wpa.htm

There was only one processor which supported "serial number" and
after the fuss that causes, the other processors were no longer
supposed to have it. So "processor serial number", isn't an issue
in the activation list. Only one particular processor, ever had
a unique internal serial number (or, so they tell us).

If you buy an exact replacement (same clock speed, like another 9550),
then there is hardly a reason for the OS to notice. If the clock speed
changes (like when I moved from a 2.6GHz to a 3.0GHz processor), the
OS can notice things like that. Or, if the processor changed
families completely, like Celeron to Pentium, Sempron to Opteron,
that too would be detected as a change.

The single biggest change, seems to be motherboard detection
via the NIC MAC address, and the weight of that might count
for more than say, a processor change. That's how Microsoft
judges a "different computer" - the new motherboard is
indistinguishable from a different computer.

I don't know all the details of a royalty OEM (Dell/HP/Gateway etc)
hardware upgrade. On the one hand, the OS normally doesn't activate
as such, as it uses "SLIC" (BIOS table says "Dell", and the
OS automatically activates).

http://en.wikipedia.org/wiki/BIOS#SLIC

If you reinstalled the OS, using a non-Dell CD with an OEM version of OS,
and used the license key from the sticker on the side of the machine, then
that wouldn't be using SLIC any more, and would be subject to the rules
in the above wpa.htm article.

Those would be my suspicions. You'll probably be able to get it
to work (at worst, it would take a phone call, if say, it didn't
activate over the network). You shouldn't be outright denied
activation, because you didn't change the motherboard. You're
allowed to change processor and RAM amount. Normally, changing
those isn't enough to "tip over" the activation scheme.

*******

From a hardware perspective, there can be a few issues with
changing the actual processor model number -

1) Vcore regulator is gutless - some motherboards can only power
a 65W or a 95W processor, and can't run a 130W processor. On
retail motherboards, the "CPU Support" list hints at power
limitations. You can "eyeball" the motherboard, and guess at
it, but that isn't very accurate. For example, if I saw a 4+1
phase Vcore regulator around the CPU socket, I'd guess that was
powerful enough for anything. Pre-built computers tend to shave
pennies off the design, by using gutless VCore regulators. I have
seen pre-built computers, that could only take a 65W processor.
We know that isn't the case with yours, because it shipped with
a 9550 already in it. But it's something to watch, if you moved to
a 130W or 140W processor.

Normally, there'd be enough power margin in the ATX supply, to handle
small differences in CPU power drain. Upgrading and installing
massive video cards though, is another matter (much larger delta in watts).

2) CPU cooler. If you build your own computer, the CPU cooler is separate
from the computer case cooling system. If the CPU isn't cool enough,
you can buy a third-party cooler to replace it (one with heatpipes).
But on Dell/HP/Acer etc. machines, the whole box may be cooled by one
fan, and a custom heatsink for which you can't buy a third-party upgrade.
So if you go from a 95W to a 130W processor, that too could be an issue.
Perhaps the issue is most obvious, when the computer makes a "whooshing"
noise, as the fan runs faster than it used to. I wouldn't want to have
to find a solution to that. Custom anything means "dremel time".

3) BIOS support. If you make a radical change (Athlon II to Phenom II X4 say),
the BIOS may not have proper support for the completely different CPU silicon
die. Microcode support could be missing. Perhaps the first hint, is a
mis-identified processor listed in the BIOS screen. (I had a motherboard
that claimed I had a "Pentium II" for example, and that was because the
BIOS was too old to recognize the actual processor type.) Sometimes this
causes no harm. Other times, the computer may not POST and boot, and you're
stuck. Or, missing microcode patch causes the OS to crash during boot.
If you changed from a 9550 to a 9650, this is unlikely to be a problem.
But grabbing just any processor, where the pins fit the socket, may not
always result in success. And that's because the BIOS doesn't recognize
the processor.

Really, I see little point in the BIOS performing those functions, but
I didn't design that crap :) Both the BIOS and the OS have microcode patch
capability, so the BIOS really doesn't have a good reason to "get stuck". But
the BIOS code can get stuck anyway. Processors should really be able to start,
without the BIOS throwing a hissy fit.

If you stick another 9550 in there, I see no problem at all. About the
worst you could do, is bend and break off a pin on it.

If you stick a 9650 in there, *maybe* there'd be an activation issue, but
I doubt it.

If you stick an Athlon 64 X2 6400+ in there, which uses more power, perhaps
the motherboard couldn't handle the VCore load.

HTH,
Paul
 
R

Rodney Pont

My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)? I understand that if you take a hard drive out of one PC and
install it in another, Windows will not work, so there must be
something in the original hardware that the Windows OS recognizes. Is
it the specific CPU, or something else on the motherboard?

Go to the HP web site and look up your model computer in the support
section. Then have a look at the documentation, it will list what
processors your system will take.
 
D

DK

My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)?

Yes and Yes.
 
J

John Doe

dk said:
Occidental <Occidental comcast.net> wrote:

Yes and Yes.

Well, Yes, but only if the CPU is supported by his mainboard.
He might be talking about a CPU that is compatible with Windows.

Also, sometimes a BIOS upgrade is required, given a CPU upgrade
that is compatible with the mainboard. I guess that possible BIOS
upgrade requirement applies as well to Hewlett-Packard.
 
Y

Yousuf Khan

My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

You'd need to get another processor that is compatible with that
processor. According to the AMD website, that processor fits into an
AM2+ socket, so any other processor that is compatible with AM2+ should
most likely work.

AMD Processors for Desktops: AMD Phenom™, AMD Athlon™ FX, AMD Athlon™ X2
Dual-Core, AMD Athlon™, and AMD Sempron™ Processor
http://products.amd.com/pages/DesktopCPUDetail.aspx?id=400

And this is a list of other compatible AM2+ processors: http://is.gd/0Am6YR
My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)? I understand that if you take a hard drive out of one PC and
install it in another, Windows will not work, so there must be
something in the original hardware that the Windows OS recognizes. Is
it the specific CPU, or something else on the motherboard?

First of all, are you sure that the CPU is the thing that failed, and
not something else, such as the motherboard itself? Or maybe the power
supply?

Regarding the BIOS, usually you won't have to update the BIOS if you
choose the exact same CPU as the one that it is replacing, or perhaps a
slower CPU. If you choose a faster CPU, then chances are it may work,
but also likely it may not work. I'd suggest looking up your HP product
page and see which were all of the optional processors supported by that
model, and also see if there are actually updated BIOSes available for
that model.

As for taking a hard drive out of one system and putting it into another
-- I assume you're talking about a boot drive -- and whether it will
work, sometimes the hardware between the two machines are similar enough
that it may work, most drivers will remain compatible, and those that
aren't might be installable at a later point. A few times, the hardware
is so incompatible between the two systems, that a lockup will ensue.
These are the two extreme scenarios, which one you get dealt is mostly
undeterminable.

Yousuf Khan
 
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O

Occidental

My PC is a 3 yr old HP Pavilion Desktop running 64 bit Windows Vista
Premium. CPU is AMD Phenom X4 9550 Quad-Core CPU. I believe the CPU
has been damaged by overheating and plan to replace it.

My question is: can I simply take out the old CPU and insert a new one
without any other changes, such as updating the BIOS? Will Windows
accept a different CPU (of the same type, or compatible different
type)? I understand that if you take a hard drive out of one PC and
install it in another, Windows will not work, so there must be
something in the original hardware that the Windows OS recognizes. Is
it the specific CPU, or something else on the motherboard?

My thanks to everyone who responded.

Go to the HP web site and look up your model computer in the support
section. Then have a look at the documentation, it will list what
processors your system will take.

Unless you are absolutely certain the CPU has failed (a relatively
rare occurrence) I suggest looking on ebay and getting a cheap replica
of the current CPU this will at least prove whether it is the CPU or
motherboard.

The answer appears to be that it will only take the original Phenom
9550, which is no longer sold. There are "used" models of this unit
available on ebay. However, they appear to be sold without heatsink.
My CPU is glued to the heatsink. Can it be removed and the new one
"attached"?

not something else, such as the motherboard itself? Or maybe the power
supply?

Here is what happened: Back when the PC was functioning, I noticed
that from time to time (usually during a comp-intensive process
(winzip, chess program)) the case cooling fan would temporarily go
into high-rev mode. Two days ago, the PC shut down while in operation.
The screen was blue (not BSOD, no text, just blue). Reboot did not
work. With the case open I discovered heavy dust accumulation all over
the CPU heatsink, including within the cooling fins. I cleaned it up
and tried to reboot. I got some of the way through the boot process,
stopping at the "insert bootable media" message. Rebooted again and
didn't get that far. Rebooted again and got nothing at all. Rebooted
this morning and got nothing, then auto shutdown, auto restart, auto
shutdown etc, which had not happened before. Does that sound like a
dead CPU? My only reservation is that I would expect an overheating
CPU to send a message to the monitor and then shut itself down. This
should be easy to implement by the OEM. Even a hair dryer has a
thermal cutout.
 
P

Paul

Occidental said:
My thanks to everyone who responded.





The answer appears to be that it will only take the original Phenom
9550, which is no longer sold. There are "used" models of this unit
available on ebay. However, they appear to be sold without heatsink.
My CPU is glued to the heatsink. Can it be removed and the new one
"attached"?



Here is what happened: Back when the PC was functioning, I noticed
that from time to time (usually during a comp-intensive process
(winzip, chess program)) the case cooling fan would temporarily go
into high-rev mode. Two days ago, the PC shut down while in operation.
The screen was blue (not BSOD, no text, just blue). Reboot did not
work. With the case open I discovered heavy dust accumulation all over
the CPU heatsink, including within the cooling fins. I cleaned it up
and tried to reboot. I got some of the way through the boot process,
stopping at the "insert bootable media" message. Rebooted again and
didn't get that far. Rebooted again and got nothing at all. Rebooted
this morning and got nothing, then auto shutdown, auto restart, auto
shutdown etc, which had not happened before. Does that sound like a
dead CPU? My only reservation is that I would expect an overheating
CPU to send a message to the monitor and then shut itself down. This
should be easy to implement by the OEM. Even a hair dryer has a
thermal cutout.

There is actually a material, that can be used for gluing integrated
circuits to heatsinks. It's called "Thermal Epoxy", due to its ability
to conduct heat.

But that would not be a preferred material, because it interferes with
the need to make repairs to the motherboard. Even when the motherboards
are new, chips need to be changed out and so on. It allows motherboard
yield at the plant to be 99.7% (only 0.3% thrown away, which is still
a large amount).

Instead, thermal paste or phase change material, is placed between the
heatsink and CPU. You can clean the material off, and apply fresh paste.

See "how to apply thermal compound", in the right hand column.

http://www.arcticsilver.com/cmq2.html

You can try to clean off the residue with IPA (isopropyl alcohol) but
it's not really an idea solvent. The nice thing about IPA is it won't
damage anything on the motherboard. You can also get purpose-made
solvents, in kit form.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100010

The main thing is, try not to get paste into the electrical area of
the processor, like on the pins of the processor or the contact area
in the socket. Some pastes are slightly capacitive, and can affect
signal shape if they ooze over everything.

To remove a CPU, try to heat it up first, by using the computer. Then,
shut down the computer, turn off the power, and while the heatsink is
mildly warm, remove the clamp (pins or bar or whatever is used), then
give the heatsink a slight twist to loosen the grip of the paste.

*******

If you had a thermal problem, it could be as simple as a broken clamp
on the heatsink. Some AMD motherboards, the heatsink downforce is set too
high, and the bar that holds the heatsink, stresses the plastic tab
on the socket until the plastic snaps. So you'd start by inspecting
to see whether the clamping method is still secure.

"Insert bootable media" means the hard drive was not detected. Note
that, if you press the reset button on the PC, that is guaranteed to
reset an IDE (ribbon cable) connected disk. But SATA drives, the reset
button doesn't do anything of note. To guarantee a SATA drive is reset,
you have to power off the PC, wait 20 seconds, then power on again.
(Note - do not "toggle" the power switch on the back in rapid succession.
Allow the inrush limiter to cool off, after the PC is switched off.
Allow a measurable time, before powering on again. That's to avoid
blowing out the supply, or causing a supply protection feature from
malfunctioning.)

The "Insert bootable media" could mean the hard drive was "hung" and
had stopped responding to commands. That could mean the disk is about
to fail soon.

I've had one "SATA hang" here, there were no long term consequences, and
I continue to use the drive. So these things happen, but should be a
relatively rare occurrence.

You can get disk test software from the disk manufacturer. For example, if
the brand on the label of the hard drive said "Seagate", I could get
Seatools for Windows or Seatools for DOS from the seagate.com web site.
It will test the hard drive, look at SMART statistics, and report
whether the drive has completely failed or not. Other third-party
programs can read the SMART statistics, such as HDTune from hdtune.com
(free edition 2.55). To do that now, you'd need to move the suspect
hard drive, into a good computer, so there is a working setup to do the
testing with.

*******

An actual "THERMTRIP" event, where the CPU overheats, causes the PC
to shut off, by using the PS_ON# control signal. The PC will not come on
again, until you turn off the power at the back, wait 20 seconds, and
turn it on again. If the CPU is still blazing hot, it would turn off
almost immediately. For example, if the CPU clamp was broken, and the
CPU heatsink was hanging there, THERMTRIP could trigger in a couple
seconds to protect the CPU. THERMTRIP is based on a temperature measurement
done on the CPU silicon die, so it's "right next to the heat".

I don't see anything to suggest the problem is CPU. There are other
things that could cause symptoms. Bad RAM. A motherboard problem.
A bad hard drive.

If I was working on it, I would have to "simplify" the setup, and
test a bit of it at a time. That means disconnecting things, then
look at symptoms. For example, set up motherboard, CPU, CPU heatsink,
no RAM, no optical drive connected, no hard drive connected, and
see if the power remains on when the motherboard is powered up.
If there is a THERMTRIP problem, presumably it is still going to be
present, when the reduced set of components are used. With no RAM installed,
the BIOS POST code will be in a "beep loop" and that is a simple
computer program of sorts. So as long as the beeping continues, the
CPU is running the BIOS code (while no RAM sticks are present).

You can dream up test cases like that, where the computer is simplified
and (relatively) non-functional, where you can still get symptom information
from the setup.

For some possibilities, while you can make measurements, component swap
is faster. Like, you can't really completely quantify an ATX power supply,
with things like a multimeter - it doesn't give a complete health analysis.
So it may be faster to just place a replacement supply in the machine
temporarily, to see if the symptoms change. Not all of the debugging
techniques need use "science" to get an answer. To properly test a
supply, takes a "Chroma Tester", a rack of equipment six feet high,
and it does a fully automated test of ATX supply parameters (static and
dynamic). And it could probably find a "weakened" supply for you. To do
that at home, yes you could do it, but it would be a month long project
with trips to the electronics store to construct dummy loads and the
like, to do even a fraction of the tests. For most users, it's easier
to just swap in that spare supply they keep for such occasions. Supply
failure is so frequent, that for some repair people, it might be their
first test. If you buy $20 ATX supplies, you might see them fail
four times a year (as reported on a Newegg reviewer comment for
a cheap supply they were buying - they said they'd bought four
of them sequentially, and they were happy that the supplies were
so cheap - a form of "false economics", as an $80 supply probably
would have lasted five years).

Staying in a loop doing restarts, could be bad RAM (CPU goes crazy
because it's running non-code), could be a weak supply (+5VSB drops
too low, causing motherboard to reset), but isn't likely to be a bad
CPU. If you saw even one proper BSOD while the computer was running,
and a particular obscure error message, that might have given a
hint of a damaged processor. But I'm not seeing anything specific
enough in your report, to narrow it down to one component. Based on
what you've reported so far, it's not definitely the CPU. Especially
"insert bootable media" - to print that on the screen, the CPU was
still running quite nicely at the time.

So you'll have to methodically test, and cook up some reduced test
cases, to prove the components in the machine. And since you got into
a reboot loop, try another ATX supply (could be weakened outputs). After
you've removed a few supplies, keeping track of the wires is no problem
at all. I can tell you though, the first one I did, I very carefully
labeled everything, so I'd get it back together again :) The first one
is scary if you've never done one before ...

Paul
 
J

John Doe

Occidental said:
My only reservation is that I would expect an overheating CPU to
send a message to the monitor and then shut itself down. This
should be easy to implement by the OEM. Even a hair dryer has a
thermal cutout.

The five dollar digital wristwatches were available before PCs
were able to keep time. My Windows XP clock hand still moves
erratically. It always has, regardless of hardware. Yes, of course
a CPU should have thermal protection. I think modern CPUs do have
thermal protection.
 
Y

Yousuf Khan

Here is what happened: Back when the PC was functioning, I noticed
that from time to time (usually during a comp-intensive process
(winzip, chess program)) the case cooling fan would temporarily go
into high-rev mode. Two days ago, the PC shut down while in operation.
The screen was blue (not BSOD, no text, just blue). Reboot did not
work. With the case open I discovered heavy dust accumulation all over
the CPU heatsink, including within the cooling fins. I cleaned it up
and tried to reboot. I got some of the way through the boot process,
stopping at the "insert bootable media" message. Rebooted again and
didn't get that far. Rebooted again and got nothing at all. Rebooted
this morning and got nothing, then auto shutdown, auto restart, auto
shutdown etc, which had not happened before. Does that sound like a
dead CPU? My only reservation is that I would expect an overheating
CPU to send a message to the monitor and then shut itself down. This
should be easy to implement by the OEM. Even a hair dryer has a
thermal cutout.

No, it doesn't sound like your CPU is broken, otherwise, you wouldn't
even get this far: you wouldn't even see the message to "insert bootable
media", if the CPU wasn't working. What it sounds like is that either
your hard disk is corrupted, or perhaps the BIOS is not pointing to it
as the boot device. If it's simply the latter, then it's a simple matter
of going into the BIOS setup and fixing it. If it's the former, then
it's a bit more involved process.

Now, it's likely that the same dust accumulation affected the CPU and
the hard disk, but after blowing off the dust, it looks like the CPU is
back to normal, so I'd look into your hard disk situation.

Yousuf Khan
 
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F

Flasherly

Even a hair dryer has a thermal cutout.

HP. Don't like saying, but reminds me of a Dell someone asked me to
looked at. The warrantee was contracted out, carried by Radio Shack,
so I just dropped it off. Utterly worthless from a pampered outlook
of deriving actual enjoyment in building a computer. Nice case, but
when I opened it for curiosity, found a proprietary Dell MB link to a
dedicated power supply. The Dell, apparently, was evincing symptoms
of a groaning stuck pig in the throes of distress, and couldn't quite
power itself up off its fat ass. Whereas, when politely inquiring of
possible causes from Radio Shack Dell customer warrantee service, upon
being told of a MB replacement, seems they'd rather as curtly I just
shut the hell up. Then again, it's an resonate theme I've encountered
at times I've opened computers with a corporate logo etched into its
carcass;- IBM and NEC, fairly to say, would probably be my worst
offenders in terms of construction designed to hinder that effort.
Although, across the board and decidedly for dollar cost averaging
purposes, buying a pre-assembled computer is surely one poor excuse
for not researching better parts, if possible, to an alternative
approach a personal build affords. Just my 2-cents. God only knows
what patience it takes to gain a confident standpoint from familiarity
with patternist, recurrent computer faults, least to mention shoddy
parts or assembly shavings.
 
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